Method and apparatus for forming round bottomed containers



Sept. 29, 1964 P. A. MOD ELLE 3,150,953

METHQD AND APPARATUS FOR FORMING ROUND BOTTOMED CONTAINERS INV TOR. PHlZ/PjZ/YZiIEZZE ikkwa 4 Sheets-Sheet 1 Filed April 15, 1959 AT 0mm);

Sept. 29, 1964 P. A. MODELLE 3,150,953

METHOD AND APPARATUS FOR FORMING ROUND BOTTOMED CONTAINERS INVENTOR PHIZIPA M00221)! Filed April 15, 1959 Sept. 29, 1964 P. A. MODELLE 3,150,953

METHOD AND APPARATUS FOR FORMING ROUND BOTTOMED CONTAINERS Filed April 15, 1959 4 Sheets-Sheet l3 ZEZQ' v INVENTOR. PHILIFfl. [100E112 BY 7% CLMLo/ui 5 A JwPA/EYJ Sept. 29, 1964 p MODELLE 3,150,953

METHOD AND APPARATUS FOR FORMING ROUND BOTTOMED CONTAINERS Filed April 15, 1959 4 Sheets-Sheet 4 {1 (KW W- i 1 {Q g;\ Q I 7'' w United States Patent 3,150,953 METHGD AND APPARATUS FOR FURMING RGUND BGTTQMED C(BNTAINERS Philip A. Modelie, Vineland, N.J., assignor, by mesne assignments, to Givens-Illinois Glass Company, Toledo,

Ohio, a corporation of Ohio Filed Apr. 15, 195?, Ser. No. 8%,562 3 Claims. (Cl. 65-109) The present invention relates to improvements in method and apparatus for forming tubular glass containers having rounded or hemispherically shaped bottoms such as test tubes, cigar tubes, culture tubes and the like.

Previously it has been conventional practice in such operations to convey short glass blanks in succession through a bottoming zone, where by employing one or more jets of pressurized fluid such as air, the closed ends of the blanks in softened condition are expandably reshaped into desired bottom formation. The procedure and apparatus which have been utilized heretofore have been such that discharge of blowing air from each blank has been uncontrollably restricted while positively retaining the blanks and blowing their bottoms during their advancing movement. The open mouths of the blanks have been held in such manner that positive and accurate shaping of the tube bottoms cannot be consistently maintained. A solid plate having one or more discharge orifices through which the issuing gas enters the open mouth of each blank has been previously used. The air discharging from the blank emits vannularly between the plate and the mouth edges in an uncontrolled restricted manner during slight lateral displacement of each blank. As a result, the tube bottoms frequently exhibit irregularly shaped contours and uneven wall thicknesses which are undesirable in high-quality glassware Variations in overall length as well as bottom wall thickness of the tubes have occurred so that appearance and subsequent service of the tubes are deleteriously affected. Good visibility through bottom surfaces of test tubes, for example, is especially desirable for viewing minor amounts of precipitates in chemical laboratory work. Such bottom misshaping of glass tubes have been primarily due to the inability of previous methods and apparatus to facilitate precisely controlled introduction and expulsion of blowing air during a bottoming operation performed in conjunction with tube conveying means. Due to the rather small sizes of the articles and their low unit cost it is especially desirable that they be fabricated in succession in a continuous automatic operation.

Accordingly, it is an object of my invention to provide novel means to overcome the above deficiencies by utilization of improved method and apparatus by which glass tubes are formed having precisely contoured rounded bottoms. The glass tubes are preheated at their closed end portions into heat-softened condition and expandably shaped in a bottoming Zone by intermittent essentially axial introduction of pressurized fluid, said fluid being permitted to emit uniformly from said tubes during their continuous positive retention.

Another object of this invention is the provision of improved apparatus which is readily adaptable to accommodate tubes of varying length and diameter applicable to reshaping their closed end portions into accurate hemispherical form.

Another object of this invention is to provide a novel method of uniformly shaping rounded bottoms of tubular glass containers during their lineal conveyance and rotation about their individual axes at a bottom expanding stage subsequent to preheating and softening their closed ends.

A still further object of this invention is the provision of a method of fabricating pairs of similar round-bot- 3,150,953 Patented Sept. 29, 1964 tomed glass tubes from cylindrical glass blanks by heatsoftening and separating the blanks and blowing their closed end portions into accurate hemispherical contour by a series of blowing steps while controlling discharge of the blowing fluid from the tubes as shaped.

A further object of this invention is the provision of novel means for expandably shaping closed end portions of glass tubes during their conveyance and axial rotation by introducing jets of pressurized air in a stepwise manner essentially axially into the tubes during several intervals of their conveyance while permitting the blowing air to discharge uniformly therefrom.

The specific nature of this invention, as well as other objects and advantages thereof, will become apparent to those skilled in the art from the following detailed description taken in conjunction with the annexed sheet of drawings on which, by way of preferred example only, are illustrated the preferred embodiments of this invention.

In the drawings:

FIG. 1 is a side elevational view of one form of appara tus for practicing the present invention.

FIG. 2 is an enlarged fragmentary plan view of a central portion of the apparatus.

FIG. 3 is a further enlarged fragmentary vertical sectional view of the closed end preheating zone taken along the line 3-3 of FIG. 2.

FIG. 4 is a vertical sectional view of the bottoming zone taken along the line 4-4 of FIG. 2 parallel to the direction of travel of the tubes and showing the open ends of the tubes at three successive blowing stations.

FIG. 5 is a further enlarged vertical sectional view of one portion of the first blowing station taken along the line 55 of FIG. 2.

FIG. 6 is a fragmentary horizontal sectional view taken along the line 6-6 .of FIG. 5 showing the flow pattern of the blowing fluid within one tube during the bottoming operation.

The subject apparatus in general comprises a horizontal conveyor which supports glass tubes spaced-apart in recumbent position with their axes transverse to the direction of travel of the conveyor. Somewhat similar conveying mechanism for another purpose has been shown in Patent No. 2,738,622 to Koenig, issued March 20, 1956, entitled Vial Necking Machines, which patent is assigned to the same parent assignee as the present application.

Tubular glass blanks of sufficient length to form a single tube may be utilized in practicing the present invention. However, for purposes of describing a preferred embodiment of the invention, glass blanks having a length greater than twice the length of two finished tubes are utilized from which pairs of similar tubes may be simultaneously fabricated.

During a major portion of their advancing movement these blanks revolve about their axes while one end moves through a preheating and softening zone in advance of the bottoming region. In the case of forming pairs of similar tubes from single tubular blanks medial areas thereof are heat-softened and separated. Following additional heating after separation and arrival of the tubes at the bottoming station, the tubes are positively restrained with their open ends held against a multiple apertured stop member in alignment sequentially with a series of pressurized fluid discharge nozzles. Following completion of the bottoming operation the tubes are carried along by theconveyor to other mechanism (not shown) for further treatment such as end glazing or flaring. g

The conveying means, which advances the tubes to the separating, preheating and bottoming stations designated by the letters S, P and B and then carries them away from the latter, is mounted upon a main supporting frame 15 closed ends (FIG. 2).

and comprises a pair of horizontal endless chains 16 trained over a pair of sprockets 17 with the upper reaches riding upon supporting rails 18.

Sprockets 17 are arranged in pairs in horizontal relation at spaced points on frame being mounted on common cross shafts, one of which shafts is driven by a motor 19 operating through a chain 20 and belt 21 with an intermediate gear reduction assembly 22. The chains 16 are moved continuously by this mechanism to advance the tubes 10 through the separating, preheating and bottoming stations. The cylindrical tubes or blanks 10 as they enter the separating station singly from a feeding chute 23 are heated and softened at a central region by a lineal series of gas flames disposed between the upper reaches of chains 16. During further preheating after separating and especially during bottoming, the tubes are continuously rotated about their axes to insure uniform thermal conditioning and shaping.

Each of the chains 16 carries an endless series of roller discs 25 arranged in pairs which are freely rotatable on chain 16. Wheels or discs 25 are employed to support the tubular blanks 10 in succession and in alignment transversely to the direction of travel of the conveyor as shown in FIGS. 1 and 2. Each pair of roller discs 25 is also applicable to supporting an individual tube lila at a central region after separation of blanks 10 (FIG. 2).

Axial rotation of the tubes 10a is effected at end preheating and bottoming stations by an integral gear 26 (FIG. 3) rigidly connected to and carried between each pair of roller discs 25. A stationary rack 27 is disposed adjacent and immediately below the upper reach of each chain 16 to engage the gear 26 of each pair of wheels or discs 25 for their rotation in the same direction when carried along by the conveyor. Thus, the upper reach of each chain 16 is aligned to interconnect with stationary rack 27 to rotate the series of roller discs 25 in the same direction and thereby the tubes 10a resting thereupon are bottoming stations P and B, although it may alternatively also extend through the initial heating and separating zone S.

A linear burner 30 adapted to direct a lineal series of burner fires upwardly to impinge upon medial regions of tubular blanks 10 is disposed between the upper reaches of chains 16 to heat-soften and separate the same into a pair of similar tubes ltla having irregularly contoured A pair of. upright rails 32 are arranged to limit outward lateral displacement of the separated tubes by the burner flames.

Separated tubes 10a which are carried along further by the'conveyor are then moved closer together by another pair of upright rails 33 in preheating zone? to bring their opposing closed ends intoproximity with another linear burner 34 disposed below the tubes and between chains 16 (FIGS. 2 and 3). The second series of burner fires 35 provided by burner 34 furnish additional heat to smooth the external contours of the closed end port ons and to further soften the glass into blowable condition.

The bottom forming mechanism which is positioned on both sides of the conveyor comprises a stationary wind box or manifold 41 which is adapted to supply blowing jfluid intermittently to each of the tubes liia.

Each blowing station manifold 41 comprises a hollow chamber 42 adapted to contain a pressurized gaseous medium such as air. A series of inlet nozzles 43 are disposed in horizontal relation spaced apart a distance substantially equivalent .to adjacenrtconveyed tubes 163a adapted 'to convey jetsr ofpressurized air from chamber 42 sequentially-into the open end of each tube as conveyed.

' Each inlet nozzle 43 is arranged with its discharge end passing'throughrupright plate 33 in alignment with an opening 46 in multi-apertured stop plate 44 (FIGS. 4, 5

6). In the blowing zone stop plate 44 has a uniform series of openings 45 extending throughout its dimensions to facilitate uniform exhaust of blowing air from the open mouths of tubes 10a juxtapositioned thereagainst during blowing. Each nozzle 43 discharges through one opening 46 in plate 44.

Article retention mechanism 70 is disposed over conveyor discs 25 in alignment with each inlet nozzle 43. A plurality of inlet nozzles, preferably three in number, is utilized in practicing the present invention. Three individual freely-rotatable wheels 71 preferably comprise the working elements of mechanism 79 and are employed to restrain the open ends of tubes 10a against apertured backup plate 44 during each blowing step. The reten tion mechanism employs vertical arms 72 to which may be attached counterweights to permit vertical movement of the wheels 71 while in rotating contact with the upper surfaces of conveyed tubes 10a. Wheels 71 are angularly disposed from the direction of conveyor travel to contact and hold the tubes 1011 against plate 44 during blowing. Alternately an endless resilient belt having its lower reach contacting the tube sides may be utilized.

Each discharge nozzle 43 is interconnected with pressure chamber 42 by a needle-type valving mechanism 50 extending essentially in alignment therewith. As shown in FIG. 5, the blowing or puffing mechanism comprises a horizontally operable rod member 51 which extends through an air-tight packing gland 52 and terminates within chamber 42 in a frusto-conical valving portion 53 adapted to seat in a similarly contoured outlet port 54 of the hollow chamber. A tension spring 55 is employed to surround rod member 51 internally of chamber 42 to maintain valving portion 53 normally seated in sealed relation.

An arm member 56 (FIG. 5) having a downwardly projecting yoke portion is firmly attached to a rock shaft 57 which extends parallel to the direction of conveyor travel above the three valving rod members 51. The lower yoke portion of arm member 56 contacts an adjustable locking sleeve 58 threaded on an outer extremity of rod member 51. Arm 56 operates against compression spring 55 when rock shaft 57 is slightly rotated clockwise to open manifold outlet port 54 and permit dis charge of blowing air into and through nozzle 43. Sleeve 58 may be adjusted and locked into position by a locking nut 59 to control the amount of blowing air permitted to enter tubes 19a While conveyed past blowing orifice 46.

Rock shaft 57 is journalled within stationary members attached to air manifold 41 as shown in FIG. 3. Each of the three valving mechanisms 54 shown in FIGS. 1 and 2 are operated simultaneously by clockwise rotation of rock shaft 57. Shaft 57 is turned by vertical movement of upright arm 60 (FIGS. 1 and 3) which is connected to rocker arm 61 having a cam follower 62 which follows rotary cam 63. Cam 63 is driven by motor 19 and belt 21 in synchronism with the conveyor so that blowing or puffing air is discharged into each tube lila when in substantially axial alignment with nozzle 43. Thus, the blowing air is introduced into each tube axially preferably three times during its axial rotation to shape the tube bottoms into hemispherical contour. The blowing air exhausts from the tube mouth in an annular pattern through openings 45 in plate 44 which surround opening 46. .Alternatively, by properly controlling the:

"is applicable to forming tube bottoms of various rounded shapes. J V summarily, the above described apparatus operates in the following manner to shape thercontainers. The tubular glass blanks are initially heat-softened and centrally separated during their conveyance in" spaced'succession 'and in recumbent position during their horizontal travel; Following separation, the closed ends are irregularly shaped having small tips or protuberances of glass extending exteriorly. The closed ends of tubes 1th: are then further heated by another series of lineal flames to soften the glass into blowable condition. The open mouths of the tubes are restrained against a multi-apertured stop plate during their movement through the bot toming zone. When juxtapositioned opposite the first blowing or inlet nozzle, the tube end is given a slightly expanded shape by the first jet of blowing fluid. The tube is then moved along further with its mouth opposite each of the next two nozzles and thereat is further expanded stepwise until a tube 30b having a truly hemispherical bottom we and uniform thickness walls is attained as it leaves the last blowing stage. The glass is then permitted to cool during further conveyance of the articles which are then carried to additional operations if desired or necessary. The manifold air pressure may be of the order of about 27 psi. and the prescribed volume or" air which is introduced at each of the three blowing points may be varied depending upon the size, length and wall thickness of the article being fabricated.

Various other modifications may be resorted to Within the spirit and scope of the appended claims.

I claim:

1. Apparatus for forming pairs of tubular glass conainers having open and rounded closed ends such as test tubes, cigar tubes and the like without the use of a tool to form said closed ends comprising means for continuously conveying tubular glass blanks in succession through a separating and preheating zone to and away from a bottoming zone, heating means disposed medially of said conveyed blanks in each of said separating and preheating zones to centrally separate and heat soften each of said blanks respectively to form similar pairs of tubes having heated closed adjacent ends, stationary means Within said bottoming zone and parallel to the conveyed direction of said containers for positively restraining laterally each of said tubes, means for axially rotating and laterally positioning the open ends or" each of said tubes against said stationary means, bottom forming means in said bottoming zone including at least two pairs of oppositely disposed fluid inlet nozzles extending through said stationary means, said stationary means including a pair of opposing multiple apertured stop plates having a substantially greater number of exhaust apertures than inlet nozzles, said exhaust apertures positioned about and between said nozzles, each pair of nozzles being adapted to introduce streams of pressurized fluids sequentially into the open ends of said tubes during an interval of their continuous conveyance and axial rotation in contact with said stop plates, said stop plates adapted to permit the ready entrance and exit of the fluid introduced into said tubes during bottom forming while maintaining the ends of said tubes free from any contact.

2. The apparatus of claim 1 in which the means for axially rotating and laterally positioning the open ends of each of said tubes against said stop plates comprises at least a pair of angularly mounted freely rotatable friction wheels disposed in alignment with each pair of said inlet nozzles.

3. The apparatus defined in claim 1, wherein said bottom forming means comprises two or more pairs of fluid inlet nozzles having the same lateral spacing as said continuously conveyed tubes adapted to introduce pressurized fiuid axially into an adjacent pair of said tubes simultaneously when in alignment therewith.

References Cited in the file of this patent UNITED STATES PATENTS 2,059,474 Meyer Nov. 3, 1936 2,103,585 Kimble et a1 Dec. 28, 1937 2,212,842 McGowan Aug. 27, 1940 2,227,224 Kimble et al Dec. 31, 1940 2,282,848 Berthold May 12, 1942 

1. APPARATUS FOR FORMING PAIRS OF TUBULAR GLASS CONTAINERS HAVING OPEN AND ROUNDED CLOSED ENDS SUCH AS TEST TUBES, CIGAR TUBES AND THE LIKE WITHOUT THE USE OF A TOOL TO FORM SAID CLOSED ENDS COMPRISING MEANS FOR CONTINUOUSLY CONVEYING TUBULAR GLASS BLANKS IN SUCCESSION THROUGH A SEPARATING AND PREHEATING ZONE TO AND AWAY FROM A BOTTOMING ZONE, HEATING MEANS DISPOSED MEDIALLY OF SAID CONVEYED BLANKS IN EACH OF SAID SEPARATING AND PREHEATING ZONES TO CENTRALLY SEPARATE AND HEAT SOFTEN EACH OF SAID BLANKS RESPECTIVELY TO FORM SIMILAR PAIRS OF TUBES HAVING HEATED CLOSED ADJACENT ENDS, STATIONARY MEANS WITHIN SAID BOTTOMING ZONE AND PARALLEL TO THE CONVEYED DIRECTION OF SAID CONTAINERS FOR POSITIVELY RESTRAINING LATERALLY EACH OF SAID TUBES, MEANS FOR AXIALLY ROTATING AND LATERALLY POSITIONING THE OPEN ENDS OF EACH OF SAID TUBES AGAINST SAID STATIONARY MEANS, BOTTON FORMING MEANS IN SAID BOTTOMING ZONE INCLUDING AT LEAST TWO PAIRS OF OPPOSITELY DISPOSED FLUID INLET NOZZLES EXTENDING THROUGH SAID STATIONARY MEANS, SAID STATIONARY MEANS INCLUDING A PAIR OF OPPOSING MULTIPLE APERTURED STOP PLATES HAVING A SUBSTANTIALLY GREATER NUMBER OF EXHAUST APERTURES THAN INLET NOZZLES, SAID EXHAUST APERTURES POSITIONED ABOUT AND BETWEEN SAID NOZZLES, EACH PAIR OF NOZZLES BEING ADAPTED TO INTRODUCE STREAMS OF PRESSURIZED FLUIDS SEQUENTIALLY INTO THE OPEN ENDS OF SAID TUBES DURING AN INTERVAL OF THEIR CONTINUOUS CONVEYANCE AND AXIAL ROTATION IN CONTRACT WITH SAID STOP PLATES, SAID STOP PLATES ADAPTED TO PERMIT THE READY ENTRANCE AND EXIT OF THE FLUID INTRODUCED INTO SAID TUBES DURING BOTTOM FORMING WHILE MAINTAINING THE ENDS OF SAID TUBES FREE FROM ANY CONTACT. 